The beamline is best suited for the structural in-situ characterization of materials in reduced dimensions, like surfaces, interfaces, thin films, multilayers and nano-crystalline compound materials. In the future there will be an increased need to study such systems under industrially and environmentally relevant conditions, such as high temperature/pressure, external mechanical forces, aggressive gas atmospheres or high electric or magnetic fields and low temperatures.

In-situ diffraction experiments at high temperatures and under gas atmospheres using heavy sample environments

Time resolved experiments to study growth kinetics and interface evolution under controlled conditions.

The heart of the experimental end station is a 2+3 diffractometer that can be operated either in horizontal or vertical sample normal mode.
The sample stage has 4 degrees of freedom in the vertical configuration and 5 degrees of freedom in the horizontal configuration. The vertical axis sample rotation stage can support a weight up to 300 kg. The detector arm has in addition two degrees of freedom combined with the possibility of slit rotation on top of the detector arm. All rotations provide an agular resolution of 0.0002°. The detector arm itself is designed to support two detectors simultaneously. The whole instrument is aligned in the incident X-ray beam using a jackable table. Two motorized horizontal and vertical slits are mounted on the detector arm. In front of the instrument another pair of slits is defining the incident beam size. Behind the incident slits an ionization chamber is installed to monitor the incident photon flux.

An in-situ oxidation chamber, as it is mounted on the diffractometer; the growth of oxide islands can be monitored in situ by a 2D and a point detector simultaneously. In the experimental hutch a crane is installed that is used to handle heavier sample environments.

2+3 diffractometer in the experimental hutch

In-situ oxidation chamber mounted on the diffractometer

The experimental stage can take up heavy duty sample environments for in situ experiments.

A simultaneous detection using a 2D and a point detector is possible.

Characteristics

Instrument characteristics

The beamline can either be operated in monochromatic, pink or white beam mode. The key parameters of the beamline are summarized in the table at the end of this section. The main optical elements are a Rh coated Si mirror and the double crystal monochromator (DCM). The mirror allows to cut the energy spectrum of the incident photons at its higher end to suppress the harmonic content in the monochromatic beam. In addition it is used to focus the beam in the vertical direction. The DCM consists of a flat Si(111) single crystal and a sagital Si(111) crystal bender for horizontal focusing. The position of the incident X-ray beam is traced by a blade beam position monitor in front of the optics. The outgoing beam can be monitored by the insertion of a fluorescence screen at the end of the optics. Two pairs of horizontal and vertical slits allow to pre-select the beam size on the sample.